NEW YORK — When members of the local historical society in Berwick found a dusty, long-ignored copy of Benjamin Franklin’s 18th-century “Poor Richard” almanac on their shelves a few months ago, they decided to find out whether it could be real. The answer was yes — emphatically confirmed on Tuesday at the Sotheby’s auction house, where an anonymous bidder paid $556,500 for the 1733 edition, the second highest price ever for a book printed in America. That was big news in Berwick, an old manufacturing city of 10,000 residents, where Franklin, using the pseudonym Richard Saunders, printed thousands of copies...